NEO Toutatis Makes a Close Pass

On September 29, 2004, a near-Earth-asteroid (NEO) named Toutatis made a close pass to planet Earth. Toutatis is in an orbit that may ultimately doom it to a collision with the Earth. In the simulation toutatis.gsim this menacing asteroid passes 1.6 million kilometers from Earth. The starting conditions for this simulation were obtained by JPL's Horizons Ephemeris Computation Service.

Toutatis is in a 3:1 mean-motion resonance with Jupiter. Using the rotating frame feature with Jupiter's period exposes this resonance.
Notice how close encounters with Jupiter raise and lower the perihelion of Toutatis, causing a change in its orbital period.
Download toutatis.gsim

(You need to have the program Gravity Simulator installed on your computer first. Click Here to download Gravity Simulator.)